JP2901078B2 - Electropolishing method for probe tip of probe card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention relates to a method for electropolishing a probe tip of a probe card.

(Prior Art) In general, a large number of semiconductor devices are formed on a semiconductor wafer by using a precision photographic transfer technique or the like, and then cut into individual semiconductor devices. Used for inspection of semiconductor devices.

That is, a probe card is a conductor pattern in which, for example, a large number of probes corresponding to electrode pads of a semiconductor device are fixed to a resin substrate or the like, and these probes and contact terminals provided at an end of the substrate are provided on the substrate surface. The structure is electrically connected. And a probe device for driving the semiconductor wafer in the XYZ directions with respect to the probe card, for example, and bringing the electrode pads of the semiconductor devices formed on the semiconductor wafer surface into contact with the tips of the probes of the probe card. A predetermined signal is supplied to the semiconductor device via the card, and the semiconductor device is inspected by a tester that measures an output signal from the semiconductor device.

By the way, in the probe card manufacturing process as described above, after a series of processes such as a process of fixing a probe made of tungsten or the like to a substrate is completed, as a final process, the state of the tip surface There is a step of polishing the tip of the needle in order to improve the satisfactorily.

As such a polishing method, a method using electrolytic polishing has been conventionally used. In the conventional method using such electrolytic polishing, for example, as shown in FIG. 3, the tip of the probe 4 of the probe card 3 is immersed from above into an electrolytic solution 2 (for example, a 0.5 to 1 N KOH aqueous solution) in a container 1. Then, a DC voltage is applied from a power supply (not shown) between each probe 4 and the electrode 5 provided in the electrolytic solution 2 to energize, and the tip of the probe 4 immersed in the electrolytic solution 2 is electrolytically polished. .

(Problems to be Solved by the Invention) However, in the conventional probe-tip electropolishing method of the probe card shown in FIG. 3, a plurality of probes 4 are provided close to each other so as to correspond to the electrode pads of the semiconductor device. To
The electrolytic solution 2 rises due to capillary action, and this electrolytic solution 2
For example, it adheres to an undesired portion such as a substrate 6 made of resin or the like and a support ring 7 provided on the lower surface of the substrate 6 for supporting the probe 4, and an adhesive for fixing these members or these members. In addition, there is a problem that a portion other than the tip of the probe and a solder portion for fixing the probe to the substrate are electrolyzed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a method for electrolytically polishing a probe card tip which can prevent an electrolytic solution from adhering to an undesired portion.

[Structure of the Invention] (Means for Solving the Problems) That is, according to the present invention, when immersing a desired portion of a probe tip of a probe card in a predetermined electrolytic solution, energizing, and performing electrolytic polishing, the electrolytic solution Form a liquid layer separated from this electrolyte solution,
A plurality of liquid layers having an interface are formed by accommodating an inert liquid whose surface tension is close to the electrolytic solution in a container to such an extent that the liquid does not move from the interface due to capillary action, and the inert liquid is formed. The method is characterized in that only a desired portion of the probe card tip from the liquid layer made of is immersed in the liquid layer made of the electrolytic solution and electropolished.

In the invention of claim 2, a desired portion of the probe tip of the probe card is immersed in a predetermined electrolytic solution, energized, and when performing electrolytic polishing, forming the electrolytic solution and a liquid layer separated from the electrolytic solution,
And, an inert liquid having a larger specific gravity than the electrolytic solution is accommodated in a container to form a plurality of liquid layers having an interface such that the inert liquid is a lower layer. Therefore, only the desired portion of the probe tip of the probe card is immersed upward in the liquid layer made of the electrolytic solution and is subjected to electrolytic polishing.

According to a third aspect of the present invention, in the method for electrolytically polishing the probe tip of the probe card according to the first or second aspect, a resistor is interposed between each needle of the probe card and a power source to energize these needles at once. It is characterized by.

(Effect) In the probe tip electropolishing method of the present invention having the above-described structure, a plurality of electrolytes and an inert liquid that forms a liquid layer separated from the electrolyte are contained in a container and have a plurality of interfaces. A liquid layer is formed, and only a desired portion of the probe card tip is immersed in the liquid layer composed of the inert liquid in the liquid layer composed of the inert liquid and electrolytically polished.

Therefore, it is possible to prevent the electrolytic solution from adhering to an undesired portion, and it is possible to prevent the substrate, the support ring, the adhesive, the solder, and the like from being deteriorated by the electrolytic solution.

(Example) Hereinafter, an example of the method of the present invention will be described with reference to the drawings.

In the first embodiment, an electrolytic solution 2 made of, for example, a KOH aqueous solution of about 0.5 to 1.0 N is provided in a lower part of a container 1 provided with an electrode 5.
And an inert liquid that forms a liquid layer separated from the electrolytic solution 2 above the electrolytic solution 2, for example, the electrolytic solution 2
And a silicone oil 10 that is less likely to react and mix with the electrolyte solution 2 and has a lower specific gravity than the electrolyte solution 2. Then, these electrolytes 2
An interface 11 is formed between this layer and the silicon oil layer.

Then, the probe card 3 is immersed in the upper layer of the silicon oil 10 so that the probe 4 is on the lower side, and the probe card 3 is passed through the interface 11 from within the layer of the silicon oil 10.
Is immersed in the layer of the electrolyte 2 by a desired length. In this state, a DC voltage was applied from a power supply (not shown) so that the electrode 5 became a cathode and the probe 4 became an anode, a current was passed between the electrode 5 and the probe 4 for a predetermined time, and the electrode 5 was immersed in the electrolytic solution 2. The tip of the probe 4 is electrolytically polished.

The power supply is performed by interposing a switch or the like between each probe 4 and a power source, and by selecting the probes 4 to be supplied with the power by the switch, power is supplied one by one to perform electrolytic polishing. Alternatively, a large number of probes 4 may be energized at one time to perform electropolishing at the same time. However, when a large number of probes 4 are energized at one time, the electric resistance varies depending on the state of each probe 4 and the flowing current differs. It is preferable to insert a resistor having an appropriate value between the power supply 4 and the power supply.

According to the first embodiment having the above structure, the electrolytic solution 2 moves between a large number of probes 4 provided in close proximity and moves by capillary action, and the electrolytic solution 2 is made of, for example, resin. It can be prevented from adhering to an undesired portion such as a support ring 7 provided on the lower surface of the substrate 6 for supporting the substrate 6 and the probe 4, and these members or an adhesive for fixing these members and the like can be prevented. Can be prevented from being deteriorated, and electrolysis of a portion other than the tip of the probe and a solder portion for fixing the probe to the substrate can be prevented.

FIG. 2 shows the method of the second embodiment. For example, as an inert liquid forming a liquid layer separated from an electrolytic solution 2 (a KOH aqueous solution of about 0.5 to 1.0 N) in a lower part of a container 1, for example, A freon 20 having a higher specific gravity than the electrolytic solution 2 is contained therein. That is, a layer of Freon 20 is formed at the lower part in the container 1, a layer of the electrolytic solution 2 is formed at the upper part, and an interface 21 is formed between them.

Then, the probe card 3 is immersed in the lower layer of the freon 20 so that the probe 4 faces upward.
The tip of the probe 4 of the probe card 3 is immersed into the layer of the electrolyte 2 by a desired length through the interface 21 from within the layer. In this state, a DC voltage is applied between the electrode 5 and the probe 4 from a power source (not shown), a current is supplied for a predetermined time, and the probe immersed in the electrolytic solution 2 in the same manner as in the first embodiment. 4 Electrolytic polishing of the tip.

In the second embodiment as well, the same effects as in the first embodiment can be obtained. Further, a gas is generated at the tip of the probe 4 in the electrolytic solution 2 with the electrolytic polishing, and this gas adheres as a bubble to the tip of the probe 4, but is arranged so that the probe 4 faces upward. Therefore, these air bubbles can be easily removed, and it is possible to prevent the electric resistance from increasing due to the air bubbles, and prevent the polishing state from becoming unstable due to a change in the energized state.

In the first and second embodiments, the case where a KOH aqueous solution is used as the electrolytic solution 2 and the silicone oil 10 and the Freon 20 are used as the inert liquid has been described. Of course, it is also possible to use. In addition, when such an electrolytic solution and an inert liquid are selected, if the surface tension of the electrolytic solution and the inert liquid is significantly different, the liquid moves from the interface due to the capillary phenomenon, so that the surface tension is reduced. It is preferable to select a combination of a close electrolyte and an inert liquid.

[Effects of the Invention] As described above, according to the probe tip electropolishing method of the present invention, it is possible to prevent the electrolytic solution from adhering to an undesired portion. , Adhesives, solder, and the like can be prevented from being deteriorated by the electrolytic solution.

[Brief description of the drawings]

FIG. 1 is a view for explaining a method for electropolishing a probe tip of a probe card according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a method for electropolishing a needle tip of a probe card according to a second embodiment of the present invention. FIG. 3 is a diagram for explaining a conventional method of electropolishing a probe tip of a probe card. DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Electrolyte solution (KOH aqueous solution), 3 ... Probe card, 4 ... Probe, 5 ... Electrode, 6 ... Substrate, 7
…… Support ring, 10… Silicon oil, 11… Interface,
20 ... Freon, 21 ... Interface.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/66 G01R 31/28

Claims (3)

(57) [Claims] 1. A method for immersing a desired portion of a probe tip of a probe card in a predetermined electrolytic solution and energizing the same to form an electrolytic solution and a liquid layer separated from the electrolytic solution when performing electrolytic polishing, and A plurality of liquid layers having an interface are formed by accommodating an inert liquid whose surface tension is close to the electrolytic solution in a container to such an extent that the liquid does not move from the interface due to the capillary action, and is formed of the inert liquid. A method for electropolishing a probe card tip, characterized in that only a desired portion of the probe card tip from the liquid layer is immersed in a liquid layer made of the electrolytic solution and electropolished. 2. A method for immersing a desired portion of a probe tip of a probe card in a predetermined electrolytic solution and energizing the same to form an electrolytic solution and a liquid layer separated from the electrolytic solution when performing electrolytic polishing, and An inert liquid having a larger specific gravity than the electrolytic solution is accommodated in a container to form a plurality of liquid layers having an interface such that the inert liquid is a lower layer, from a liquid layer made of the inert liquid, A method for electropolishing a needle of a probe card, characterized in that only a desired portion of the needle of the probe card is immersed upward in a liquid layer made of the electrolytic solution and electropolished. 3. The method according to claim 1, wherein a resistor is interposed between each needle of the probe card and a power source to energize these needles at one time. Electropolishing method of the probe tip of the probe card.